Flywheel chatting
Thread Starter
4th Gear
Joined: Jul 2012
Posts: 4
Likes: 0
Flywheel chatting
I upgraded my 1980 corvette with a 454 engine and have a question. Is there a difference in 11” flywheels when using the original bellhousing for the 350 that was in it? After installing i had a grinding so i took apart and the inside of bellhousing was marked 1-2” all around the inside. What gives.
Racer
Joined: Apr 2009
Posts: 331
Likes: 44
From: Cincinnati Ohio
Sounds like you are trying to put a 168 tooth flywheel in a bell housing that was designed for a 153 tooth flywheel. Small blocks used the smaller flywheel, big blocks and the 400 used the larger flywheel. You probably had problems with the starter as well.
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,501
From: Little Rock AR
454 uses an external balance flywheel. The 350 does not use that. Make sure you have that right.
Starter nose cones are different betwen large and small flywheels/bell housings unless you have a multi fit aftermarket starter. Bolts in-line fits smaller flywheel. Diagonal bolt hole pattern is large diameter flywheel. If the flywheel is rubbing it does not match.
You can not mix and match the sizes of the flywheel, clutch, bellhousing.
Starter nose cones are different betwen large and small flywheels/bell housings unless you have a multi fit aftermarket starter. Bolts in-line fits smaller flywheel. Diagonal bolt hole pattern is large diameter flywheel. If the flywheel is rubbing it does not match.
You can not mix and match the sizes of the flywheel, clutch, bellhousing.
Thread Starter
4th Gear
Joined: Jul 2012
Posts: 4
Likes: 0
Thank you for your replies.
My 1980 corvette 350 has the 168 tooth flywheel and 11” clutch. The 454 I installed has the same setup. I asked almost everyone i knew and they were informed that all bb 63-81flywheel were external balanced. Now i understand this is not the case.
Do balancing plates work? Where do i find a true 454 flywheel?
thank you in advance
My 1980 corvette 350 has the 168 tooth flywheel and 11” clutch. The 454 I installed has the same setup. I asked almost everyone i knew and they were informed that all bb 63-81flywheel were external balanced. Now i understand this is not the case.
Do balancing plates work? Where do i find a true 454 flywheel?
thank you in advance
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
no. 427 and 396 and 366 truck used internal balanced cranks and 2 piece 168 tooth 350 flywheels will run on them. the 454 and 400 small block take external balanced flywheel/ the 1 piece 350 is also ext balanced, but much less weight and flywheel side only. and this flywheel will not fit anything else. i believe all 1 piece small blocks are balanced the same to the same 350 flywheel, even 383. but i digress. put the 454 and 350 flywheels side by side. same height? are you running the 350 clutch? what is hitting inside? the flywheel or clutch pressure plate? engine still in the car? put flywheel on and bellhousing. now you have a big hole to look in to see how flywheel fits. https://www.ebay.com/itm/26512666230...oAAMXQjq5Q9g8F. that is the half *** method. 2nd link new chinese. will probably work. https://www.ebay.com/itm/30390587549...8AAOSwYmVgPqve 3rd link used oem. will definitely work but may need resurfaced. https://www.ebay.com/itm/29373527042...0AAOSw6a5fX~4Z see jegs and summit too.
Last edited by derekderek; May 15, 2021 at 10:11 AM.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
on 454 flywheels. i have heard people say gen 5 and 6 flywheels are balanced differently than MK 4 90 and earlier 454's. i have heard engine builders say makes no diff and interchange just fine. i also see veery few places even making note of which year their aftermarket flywheel is. do some homework before buying. you don't have to drive this thing to work on monday. you can find new under 100 and also spend 450 bucks. drag strip you want heavy weight and billet steel. road racing you want light weight. regular driving you want regular weight...
Thread Starter
4th Gear
Joined: Jul 2012
Posts: 4
Likes: 0
Dereck thanks for the reply, im using the 454 clutch and flywheel that came with engine. It fits with clearance in the bellhouse that came with vette. Aluminum type for 4sp Super T10.
but the groves in bellhousing are extending into the bellhousing. Can a flywheel and clutch assembly move in and out, back and forth with in the bellhousing? It’s weird because the marks are all the way around. The starter is not effected. Runs great but does have a noise some time when you rev it up when not under load.
again everything is 454 except the bellhousing. All the books and people i talk with say there is no difference in Chevy bellhousing.
but the groves in bellhousing are extending into the bellhousing. Can a flywheel and clutch assembly move in and out, back and forth with in the bellhousing? It’s weird because the marks are all the way around. The starter is not effected. Runs great but does have a noise some time when you rev it up when not under load.
again everything is 454 except the bellhousing. All the books and people i talk with say there is no difference in Chevy bellhousing.
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Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,501
From: Little Rock AR
168 tooth flywheels come 3 ways:
1. Neutral balance when used on a 350 or 396/427.
2. External balance with a lighter counterweight for the 400 (or used for external balanced 383 stroker).
3. Heavier counterweight for externaly balanced 454.
1. Neutral balance when used on a 350 or 396/427.
2. External balance with a lighter counterweight for the 400 (or used for external balanced 383 stroker).
3. Heavier counterweight for externaly balanced 454.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
454 and 400 use the same flywheel casting. then they drill the flywheel a LOT to rebalance for the 400. a guy sold me a 454 flywheel for my 400 in a boat. bow rails vibrated back n forth at idle like you wouldn't believe. i believe his 168 tooth 350 clutch would also hit the 153 tooth housing. can the flywheel move back and forth? if the thrust gearing in the 454 is shot. put a big screwdriver between 454 and flywheel and see if you can pry it away from the engine. 20-30 lbs of force. not enough to bend the screwdriver. you should have no end play in that crankshaft. lay flywheels and clurtches side by side and post pics.
Last edited by derekderek; May 15, 2021 at 11:27 AM.
Race Director
Joined: Jun 2000
Posts: 10,045
Likes: 675
From: FL
on 454 flywheels. i have heard people say gen 5 and 6 flywheels are balanced differently than MK 4 90 and earlier 454's. i have heard engine builders say makes no diff and interchange just fine. i also see veery few places even making note of which year their aftermarket flywheel is. do some homework before buying. you don't have to drive this thing to work on monday. you can find new under 100 and also spend 450 bucks. drag strip you want heavy weight and billet steel. road racing you want light weight. regular driving you want regular weight...
https://www.onallcylinders.com/2018/...evy-big-block/
Summary.
Mk IV BBC - 33.0 ounce-inch balance weight
Gen 5/6 with cast crank - 42.5 ounce-inch balance weight
Gen 5/6 with forged crank - 41.7 ounce-inch balance weight
One ounce of imbalance located one inch from the crank centerline will create an imbalance force equivalent to 31.9 pounds at 6,000 rpm. At 2,000 rpm, it would be 3.5 pounds of force. It’s possible that you could feel that imbalance even at 2,000 rpm.
I solved that problem on my 496 by having the 4340 forged rotating assembly internally balanced.
Back to the OP. Honestly, I am not sure how it would have bolted up if it was hitting the flywheel. Possible that you have an endplay issue.
Also, I would highly recommend dumping the stock bell housing and getting an SFI unit like Quicktime. Much more peace of mind.
